The world of polymers has progressed rapidly to transform material science from wood and metals of the 19th Century to the use of thermoset polymers of the mid-20th Century to the use of thermoplastic polymers of later 20th Century.
Thermoplastic elastomers (TPEs) combine the benefits of elastomeric properties of thermoset polymers, such as vulcanized rubber, with the processing properties of thermoplastic polymers.
Recently, a new type of TPE has become available, namely: ethylene/alpha-olefin interpolymers as disclosed in PCT Patent Publications WO 2006/101966; WO 2006/102155; WO 2006/101999; WO 2006/101928; and WO 2006/101924 all filed by Dow Global Technologies and all incorporated by reference as if fully rewritten herein.
During manufacturing, particularly in the food and medical industries, it is important to provide a mechanism for individual products to be marked with indications of serial number, lot number, production control numbers, etc., in order to provide sufficient information on the product for regulatory purposes, inventory control purposes, working capital management, purposes, and unfortunately if necessary, product recall purposes.
British Patent Publication GB2352824 (abandoned) discloses a TPE and pigment for UV laser marking. The pigment range identified as useful is 0.5-5 weight percent of the total compound. Because the pigment for UV laser marking is a key ingredient, its cost affects the price and acceptability of using UV laser marking upon a TPE. But as stated in GB2352824, laser marking using UV wavelengths is far preferable over using lasers of other wavelengths which scar or burn the information into the surface of the TPE.